The present invention relates to the art of drilling and more particularly to a drilling fluid processing system. The present invention provides a system for processing drilling fluids that includes method and apparatus for protecting the equipment during transit, that allows the equipment to be installed easily and quickly at the work site, that allows the equipment to be easily and quickly inspected and, if necessary, adjusted and/or repaired and that allows the equipment to be easily and quickly removed from the work site.
In drilling a well for oil, gas and the like, the drill bit is supported in the well bore by drill pipe. The drill pipe is hollow composed of a plurality of individual lengths of pipe connected together. The drill pipe carries drilling fluid in its interior down to and through the drill bit. The drilling fluid reaches the bottom of the well bore and passes upwardly in the annulus between the exterior surface of the drill pipe and the interior surface of the well bore to the surface and then through a return pipe to storage pits on the surface commonly referred to as mud pits.
The drilling mud is ordinarily an aqueous suspension of solid matter generally containing minerals such as bentonite and barite. The drilling mud lubricates and cools the drill bit and serves as a carrier to withdraw drill cuttings and debris from the well for disposal. The drilling mud also provides a pressure seal in the well bore to prevent the escape of gases from the well. The pressure exerted by the column of drilling mud normally is greater than the pressure which may be released upon encountering gas pockets as the well is drilled. The column of drilling mud counteracts gas pressure and prevents blowouts but very often becomes contaminated with the gases encountered during the drilling operation.
Under most circumstances it is necessary that materials such as the drill cuttings, debris and the gases be removed from the drilling mud. Since it is economically unfeasible to discard the returning drilling mud, it is necessary to process the mud to remove the drill cuttings, debris and gases and recirculate the drilling mud through the borehole. Removal of the contaminating gases is especially important because they may be poisonous or highly explosive and the release of such gases into the atmosphere would present a substantial risk to personnel in the drilling area. The presence of gases in the drilling mud decreases its weight and affects its viscosity often rendering it unsuitable for recirculation through the borehole. When gases are contained in the drilling mud being circulated through the borehole, it increases the danger of a blowout in the well.
The present invention provides a system to protect the drilling fluid processing equipment from damage in shipment and in installation and operation at the work site. The drilling fluid processing equipment in the preferred embodiment of the invention consists of a pump with an elongated drive shaft supported only by bearings at the motor end, leaving the shaft housing vulnerable to bending. The present invention simplifies installing the equipment by avoiding the necessity of providing a special high-lift hoisting unit to place the equipment in position in a pit. The present invention combines the function of a shipping skid with that of a working support when the equipment is installed and avoids duplication of accessory equipment. The present invention provides means to raise the equipment out of the drilling fluid for access for inspection and/or repair.